Flexible shaft coupling



Ug. 16, 1949. l A, Tl BARAGER v 2,478,890

FLEXIBLE SHAFT lCOUPLING Filed Deo. 10, 1946 5 Sheets-Sheet l Afro/17M ys A. T. BARAGER FLEXIBLE SHAFT COUPLING A3 Sheets-Sheet 2 5V www ATTOF/VE VS Aug. 1K6, 1949.

Filed Dec. 10, 1946 Aug-1651949. A; T. BARAGER 2,478,890

FLEXIBLE SHAFT COUPLING l Filed Deo. 10, 194e 3 sheets-sheet s A 0F 72 a( @lili/W. M

v ATTORN YS Patented Aug. 16,V 1949 Umano :s TME-s rare N T Aorf-Fl n2,478,890 FLEXIBLE vSHAFT?COUPI'ING Alfred'l .Barageny Buffalo, NI Y.. Y t"pllicatnf(wennbet 10, 194%,Seiil'-N0f715I71 This invention relates to a flexiblefshaft coupling lwhich 'fis .more `.particularly designed 'fior operatively :connecting two shafts .which are slightly rout *of axial alinement and permit :of

transmitting. mot-ion v.from e one of these v'shafts '..to the' other-without producing anysbindingor heat- :One-@0f .the objects :of .this invention; is to 'provide' a shaft coupling which). isacompact. and `sturdy in :Construction :and Whichxincludes :no rscrews, nuts or` pins thatareliable Ato get `loose -and only .oneinternal spring for yieldirrglyfholding some of the partsimpoSitiOrl.

Another' .object of this invention-.iste provide anfenclosure for theccoupling which protects the YWorking parts from dustfand dirtfand-also has a relatively :smooth `:exterior and .no f-depressions, thereby avoid'ing" colleetingfof. foreign. matter.` and also eliminating `any hummingseffectwhich'would be' .liable to occur ifany air'pocketsfexisted onthe exterior of the enclosure.

-A further object V1 of this invention ais `:to construct the.:enclosure:2that .the same also serves to hold alubricant: which is supplied/totheworking parts and Y:elrialcles ''them :to operate without gappreciable friction orfwear.

1A :still .'further'object @of this invention is to so-organize the .several parts l.thatflost motion between.the samefis lavoided-fand vibration isreduced lto a minimum.

In. the accompanying drawings.:

Fig. 1 :is a plan-#view .ofca shat-.couplingembodying A.this ...invention `.and showing .the enclosingcasinginssection. l

V2 .is alongitudn'al `section `of the h.same taken on line 2-42. FgA.

.tig...3 is an end view of-.the .coupling partly broken away.

Fig. Lisatransverse setion.taken.on.l.inet44, Fig. 2.

Fig. Eis an edge viewV f the sprngforminglpart of the meanslfor sealing the enclosing casing'o'f the coupling.

Fig. 6. is .a'front view of thesaine.l

'Fig."7 'is.a,"lo'n`g'ltudinal section o'f a'modiiied form of this'invention vWhichis somewhat'more compact. lengthwisethan'the constructicm shown in .Figsj1-4' and. takenon" Iinel-1,`Fig. 8.

"FigJ' isa transverse section vtakenfoniinefB-V', Fig. 7.

In the `following `description."slnlilar reference characters indicatelikeparts 'inthe several figures ofthe drawings.

Referring to lthe :construction shown Figs. I-4,` thenumeralssfrepresent" twos'hafts'which .3.-Claims. (Cl. 64-.17)

haveitheir.'correspondingfends 'arranged substantially end to-.end and'whichcare-'fadapted tof-be connected by the-coupling .'frthls inventionso that motion can 'be transmittedfrom :onefshaft .to .'the other .Whenthe .same are: in"alinement:or somewhat outiof 'alinement -This ecoupling "comprises two l`couplizzlg heads VYcludesfet-rear.tubularihulc Hl whichls secar-.edito vvtheen'd of one of '-tlae'shafts inzany. suitablemanner and "two-longitudinal coupling 'armsflil projecting forwardlylrom the "front en'dfof lthis .hub on diametrically `opposite sides V.of'itherfsame In the assembled position Tof thettwocouplin'g heads, the farms of :one .headvfsarezarranged Lin l the spaces betweenithe arms oi" theiotherfhea'd and thelseveral iarms .of l"both .heads yare fspaced .in equal quarters .in Va :circumferential rrow around *..the axesof theselshafts.

.Each fof the icoupling `arms .is providedfon its front `.end Wltharadi'al guideway:havingpreferably -the form of 1a l. guide 1 opening Whichzis crecitamgular' in crossfsection andpmifidedwithttwo circumferentially opposite 'guide `Walls for' faces I2 which are parallel :with a' radial: line .'fromthe axisy of the respective 'hubfa rear stop Waller'zsurface t3-'and two front stop; surfaces arranged onopposite .sides of afslot l 5' .formed in'rthe front wall of this opening, `By'providingtithe'frontfsidr: of 'the guicleway in each :coupling 'arm Jwith radial slot .it is .possible to'machine .this guideway 'easily :and-at less Ycost than.v if i thesame :were made in iany :other Way, such aas .breaching :or casting.

Withn'each of fthesezguide openings issarl-V ranged-.a guide block f I 6 :which .isgprovided -zcentrally .with a radialibearmg opening. 1 Tandmljts circumferentiallyzopposite sdesf'wthfttwoparailei guide f faces la' which. slidinglyz-engage the guide faces i`l2 'of "the guide :ropeningfinethe-frespective arm, and front andllear: stop faces N520-adapted to engage thefrontfand rear'.stop:surfacesla?1 H on said arm.

yBetweenthef'itwo coupling heads is aan-anged a spider havingv a'LbodyZl "which is ,preferably cross-shaped and provided with four pivot jgpins or trunnions 122 VVwhich `project .fradially :outward and 'are arranged: equ'idistantin `anranrmlarrow around the bodyl `Each of these Ipvot :pins journald-in l'the 'bearing :opening ll .of .one vvof the guide blocks so that duringzfthe use-1.0i this coupling-eachbearing block and the erespective pivotipinsffaref-capable of .iturnmg relativexaione another and the 'block fand ipivot 'pin @can also slide v'rauialiy one frlatvetto f'ftlxe Esther. mach block and its pivot pin are compelled to rotate bodily in unison about the axes of the shafts due to engagement of the circumferentially opposite sides I8 of the bearing block with the guide faces I2 of the coupling arms but this block and pivot pin are free to move lengthwise in the guide opening in the respective coupling arm if the shafts move lengthwise toward and from each other, the extent of such movement being limited by the front and rear stop faces I3, I4 on this arm. By these means rotation of one shaft is transmitted to the other and several parts are free to adjust themselves relatively the required extent if the shafts are not in exact alinement and thus avoid cramping and heating as well as eliminating undue wear and cost of maintenance.

Means are provided for enclosing the working parts of this coupling so as to protect the same of the injurious effects of dust and dirt and also to permit of lubricating these parts so as to maintain the same in the best working condition. In their preferred construction these protecting means are constructed as follows:

V'lhe numerals 23 and 24 represent two cupshaped casing sections which together form a casing of substantially globular form which encloses the adjacent parts of the heads and the spider of the coupling and the parts mounted thereon. These casing sections are detachably connected by means of a screw joint 25 between the inner peripheral edges and the same are provided, respectively, on their outer sides with central openings which receive the inner parts of the hubs of the coupling heads. A tight joint is provided between this enclosing casing and the hubs of the coupling heads so as to exclude dust from the interior of the casing and the working surfaces of the coupling and also permit of filling the casing with grease or the like for lubricating the Working surfaces and prevent the lubricant from leaking to the exterior of the casing. This is preferably accomplished by providing sliding joints between the opposite ends of the casing and the hubs which in their preferred form are constructed as follows:

The numeral 26 represents an annular concavev sliding surface formed on the edge of the central opening in the casing section 23 and engaging with an annular convex sliding surface 2l on the inner part of the hub I0 of the coupling head which is connected with the shaft 8, which surfaces are curved and form part of a sphere, the axis of which is located at the center 28 of the spider, thereby forming a universal joint which permits the shaft 3 and the parts connected therewith to turn in all directions without disturbing or opening the joint between the casing an'd the hub on the shaft 8.

On the inner side of the central opening of the other casing section 24 the same is provided with an annular concave sliding surface 29 which engages with an annular convex sliding surface 3U on an outer closure or sealing ring 3l. The cooperating sliding surfaces 29, 30 form part of a sphere, the axis 2B of which is located in the center ofthe spider so that the joints between the outer sides of both casing sections and the respective parts of the coupling are concentric and cause the parts tobe capable of turning universally in all directions in the manner of a ball and socket joint.

The bore of the outer closure or sealing ring 3Il is provided with an annular concave sliding surface 32 which engages with an annular convex sliding surface 33 on the periphery of an 4 inner closure or sealing ring 34 which surrounds the adjacent inner part of the hub I0 of the other coupling head. The curvature of the cooperating sliding surfaces 32, 33 form part of a sphere, the center of which is located on the longitudinal axis of the shaft 9 and the coupling head mounted. thereon, as shown at 35 in Fig. 2. By these means the shaft 9 is free to incline laterally in all directions relative to the spider and the enclosing casing without causing any binding or cramping action between the respective parts and still maintain the casing leak-tight and prevent any lubricating grease therein from escapmg.

The bore 36 of the inner closure or sealing ring Y 34 is cylindrical and is capable of sliding lengthlmi wise on the cylindrical periphery 31 of the hub I9 secured to the shaft 9 and thus permit this inner closure ring to adjust itself to suit the changes in the relative position of the shaft 9 and the casing.

The outer sealing ring 3l is yieldingly held in engagement with the casing by spring means consisting preferably of an annular deformed spring 38 which surrounds the hub I0 attached to the shaft 9 and bearing with its outer side against the inner side of the outer sealing ring 3| while its. inner side bears against the outer side of an annular flange 39 on the hub Il! of the head which is attached to the shaft 9. This flange is preferably provided with an annular groove 4I] which receives the inner part of the spring 38 and holds the same in a central position. As the spring 38 presses the outer sealing ring 3l outwardly, it carries the inner sealing ring 34 with it, due to the interlocking effect of the spherical joint surfaces between the same, thereby insuring sealing the casing at this place against leakage.

During the rotation of the fiexible coupling together with the shafts which it connects the guide blocks are thrown outwardly by centrifugal force 'at which time the same slide radially on the coupling arms I I and their outward radial movement is limited by engagement of the'outer ends of the guide blocks with the inner side of the longitudinal central part of the enclosing casing'. In order to permit these guide blocks to thus engage the enclosing casing and still enable the two coupling heads to turn freely in all directions relative to one another while adapting themselves to any misalinement therebetween when in operation, each of the guide blocks IS has its outer end provided with a spherical convex rounded face 59 the aXis or center of which is located at thecenter or middle 28 of the spider, thereby permitting the outer ends of the guide blocks IB to turn, slide freely in all directions in engagement with the inner side of the enclosing casing,v and limit the radial outward movement of the guide blocks without causing any binding or cramping action against the same.

When considerable space is available between the opposing ends of the two shafts 9 and 9 which are to be coupled, the inner ends of the hubs I9 of the coupling heads may be closed by a web 4I, as shownin Fig. 2, in which case the coupling may be made of comparatively small diameter, but when the ends of the shafts are close together, the inner ends of the hubs Ill may be left open and project into an opening i2 in the center of the spider, and the coupling may be made of larger diameter, as shown in Figs. '7A and 8. In other respects the two forms of couplings are substantially alike in construction and operation and the foregoing description therefore applies equally to both of them.

The guide blocks I6 are compelled to turn bodily with the coupling heads about the longitudinal axis of the coupling by engagement of each pair of guide side faces I2 on the coupling arms with the circumferentially opposite side faces I8 of each guide block, as shown in Figs. 1, 3 and 4, but each of the guide blocks is free to move lengthwise of the axis of the coupling between these side faces I2 and thus compensate for play or slack which may occur between the opposing end of the shafts due to any longitudinal movement of these shafts relative to one another which may occur during the operation of the same. This manner of mounting the guide blocks I6 on the coupling heads also permits the same to assume an angular position relative to one another when the axes of the shafts are not in exact alinement but are arranged at an angle to'one another. To permit of such longitudinal rocking and sliding movement of the guide blocks I6 between the side guide faces I2, the outer and inner stop faces I3 and I4 of each couplingY arm are spaced from corresponding inner and outer faces I 9 and 20 of the respective guide block and thus provide the required clearance necessary for this longitudinal movement of the guide block relative to the respective coupling arm. The stop faces I3 and Iii also serve to maintain the guide blocks I 6 in an assembled position on the coupling arms while handling the parts in the course of manufacture.

In order to maintain the spider in a central position relative to the coupling heads and associate parts and thus prevent the coupling from becoming unduly unbalanced while rotating, the spider is provid-ed with an annular row of stop faces 5I which are preferably formed around the inner parts of the trunnions 22, as shown in Figs. 2, 3 and 4, and adapted to engage the inner ends of the guide blocks in the event that the spider is thrown radially by centrifugal force during the rotation of the coupling.

From the foregoing description it will be noted that due to the sliding action of the guide blocks I6 on the guide faces I2 the two shafts are compelled to turn in unison at all times, thereby avoiding any jolting or hammering action when starting or stopping rotation of the shaftsk and coupling.

Inasmuch as the outer ends of the guide blocks are spherical and bear against the inner side of the casing due to centrifugal force when the shafts are rotating, these blocks always assume their proper position in accordance with the relative angularity lbetween the shafts.

Moreover any lateral movement of one shaft relative to the other is permissible by the trunnions sliding endwise in the respective guide block, this movement being limited by the shoulders 5I on the spider engaging with the inner ends of the guide blocks.

Outward movement of the guide blocks is limited by engagement of the same with the inner side of the casing and lengthwise movement of the shafts is governed by the clearance between the inner and outer sides of the guide blocks and stop faces I3 and I4 on the coupling arms II.

It is to be particularly noted that in this coupling friction between the several parts is virtually eliminated and thus allows the two shafts which are connected by this coupling to turn in their respective bearings with a minimum of friction, thereby avoiding undue Wear on the parts and reducing the cost of maintenance accordingly.

As a whole this coupling is very strong and capable of readily transmitting the heaviest loads from one shaft to another without liability of giving way. The same is also so organized that the same is capable of use in places Where only a limited amount of room is available and the same can also be easily disassembled for inspection, adjustment and repairing if this should be necessary at any time.

I claim as my invention:

l. A coupling for connecting two relatively movable rotatable members, comprising two coupling heads adapted to be connected, respectively, with said members and-each head having radial guideways which are spaced circumferentially from like guideways on the other head,

guide blocks slidable radially on said guideways, a spider arranged between said heads and having radial trunnions on which said guide blocks are capable of turning and also sliding radially, and a casing enclosing said heads and spider and mounted on said heads, the outer end of each of said guide blocks being rounded and engaging with the inner side of said casing.

2. A coupling for connecting two relatively movable rotatable members, comprising two coupling heads adapted to be connected, respectively, with said members and each head having radial guideways which are spaced circumferentially from like guideways on the other head, guide blocks slidable radially on said guideways, a spi-der arranged between said heads and having radial trunnions on which said guide blocks are capable of turning and also sliding radially, and a casing enclosing said heads and spider and mounted on said heads, the outer end of each of said guide blocks being of spherically rounded convex form, the axis of which is located at the center of said spider.

3. A coupling for connecting two relatively movable rotatable members, comprising two coupling heads adapted to be connected, respectively, with said members and each head having radial guideways which are spaced circumferentially from like guideways on the other head, guide 'blocks slidable radially on said guideways, a

' spider arranged between said heads and having radial trunnions on which said guide Ablocks are capable of turning and also sliding radially, and a casing enclosing said heads and spider and mounted on said heads, and said guide blocks engaging their outer ends with the inner side of said casing and said spider being provided with stop shoulders which are adapted to engage with the inner ends of said guide blocks and thereby limit the lateral movement of said spider relative to said heads.

ALFRED T. BARAGER.

REFERENCES CITED The following references are of record in the iile of this patent:-

UNITED STATES PATENTS Number Name Date 135,404 Cathcart Feb. 4, 1873 1,313,109 Ofeldt k Aug. 12, 1919 2,346,058 Waldron Apr. 4, 1944 FOREIGN PATENTS Number Country Date 515,424 Germany 1931 

